Algebra
posted by sharon .
Will be the graphs of each of these equations be perpendicular.
1.y=7x9
slope=7
yintercept=9
2.3y=21x+7
y=7x(7/3)
slope=7
yintercept=(7/3)

They are perpendicular if the product of their slopes is 1.
So, is (7)(7) = 1 ?